People were complaining that Call of Suzerain was buggy, so I did some testing.
What I found out was:
When you have 0 lords, Call of Suzerain always works.
If you already have 1 lord, Call of Suzerain will never give you 2nd lord offer, unless your empire is strong. And your empire is weak in early stages of the game.
You can dismiss your existing heroes and reject new ones, Call of Suzerain keeps offering lords. If you dismiss/reject hero, it might be randomly offered again. (for example, in my test, I had 5 black mage offers.
I leveled first one to lev 3, then dismissed it. New Black Mage was offered again later, I accepted, and it was brand new level 1 black mage)
If your empire is strong enough (it happened to me after turn 70 in my casual test game), Call of Suzerain will always give you 2nd hero offer. Note: if you loose lots of units and become weaker, Call of Suzerain will stop giving you 2nd hero offer.
If you would get natural hero offer, call of suzerain might give you additional hero offer, so you will have 2 offers at the same time.

What I found out was:
When you have 0 lords, Call of Suzerain always works.
If you already have 1 lord, Call of Suzerain will never give you 2nd lord offer, unless your empire is strong. And your empire is weak in early stages of the game.
You can dismiss your existing heroes and reject new ones, Call of Suzerain keeps offering lords. If you dismiss/reject hero, it might be randomly offered again. (for example, in my test, I had 5 black mage offers.
I leveled first one to lev 3, then dismissed it. New Black Mage was offered again later, I accepted, and it was brand new level 1 black mage)
If your empire is strong enough (it happened to me after turn 70 in my casual test game), Call of Suzerain will always give you 2nd hero offer. Note: if you loose lots of units and become weaker, Call of Suzerain will stop giving you 2nd hero offer.
If you would get natural hero offer, call of suzerain might give you additional hero offer, so you will have 2 offers at the same time.
